In order to splice coated optical fibers, it is necessary to remove the coating of the coated optical fibers to be spliced for a prescribed length. There is proposed a method for removing the coating without damaging the coated optical fiber as well as deteriorating the optical fiber.
Japanese Patent Application Publication No. 2002-90551 discloses a method for removing the coating in the intermediate portion of the coated optical fiber without deteriorating the strength of the optical fiber.
According to the disclosed method, the coated optical fiber comprises the optical fiber and a primary layer and a secondary layer of UV-cured resin coated on the optical fiber. Both ends forming the intermediate coating removal zone between thereof are cut into the primary layer in the circumferential direction to form two incision ends. Then, a cutting blade is placed at one of the incision ends and proceeded into the primary layer, and thus proceeded cutting blade is moved to the other incision end of the intermediate coating removal zone in the longitudinal direction, thus removing the coating without damaging the optical fiber so that optical fiber (i.e., glass portion) is partially exposed. Furthermore, the remaining coating in the intermediate coating removal zone is dipped in an organic solvent so that the remaining coating is swollen.
Japanese Patent Application Publication No. 1994-94925 discloses a method for removing coating of the coated optical fiber to splice the coated optical fiber in which the coating in the end portion of the coated optical fiber is removed.
According to the disclosed method, a hot stripper is employed. More specifically, the coated optical fiber, in which the coating having outer diameter of at least 300 μm is coated on the optical fiber having outer diameter of 125 μm, is removed using the hot stripper. Upon removing the coating, a resin layer having outer diameter of at least 400 μm is formed on the outer peripheral of the coating in the portion to be removed, and then the coating to be removed together with the resin layer is removed by the hot stripper. According to the above described method, the coating of the fine optical fiber having outer diameter of up to 300 μm (i.e., outer diameter of the coating) can be removed by the hot stripper without damaging the optical fiber as well as largely deteriorating the strength of the optical fiber.
An etching technology using plasma is disclosed in the Surface Technology, Vo. 55, No. 12, 2004, P38 to P42. According to the above, it is disclosed that the atmospheric plasma has been used as the means to irradiate on a flat plate. More specifically, it is reported that the ultrahigh speed etching of the silicon dioxide film by the plasma of He, NF3, H2O gases at the SiO2 etching speed of 14 μm/min is successfully performed. Furthermore, it is disclosed that the Si is not almost etched, and the etching selectivity is at least 200.
Japanese Patent Application Publication No. 2005-235464 discloses a plasma generating apparatus used for synthesis of fluorocarbon gas which is used in the etching process and film forming process in the semiconductor fabricating process. According to the above described plasma generating apparatus, it is possible to generate the stable plasma at atmospheric pressure.
Japanese Patent Application Publication No. 2004-353066 discloses a plasma source and an apparatus of processing the plasma to be applied to the semiconductor fabricating process. The plasma source includes a hollow cathode electrode member having a plurality of through holes, arranged at the gas flow-out side of the gas supply chamber. The plasma source enables a micro cathode plasma discharge within the through holes in the hollow cathode electrode member. According to the above described apparatus of processing the plasma, a high density of plasma can be highly effectively generated. Japanese Patent Application Publication No. 2005-129692 discloses an apparatus and the method of processing electronic components using the plasma.
More specifically, there is disclosed the method of processing the electronic components including terminal portion, in which the plasma generated with the use of a mixed gas comprising noble gas, oxygen and fluorine (the ratio of the noble gas is within a range of 90% to 99.9%) is irradiated to the terminal portion comprising a coated wire in which the surface of the wire having cupper as its main ingredient is coated by resin. According to the above described method, the plasma can be locally generated so as to remove the enamel coating in the portion of the terminal portion.    Patent document 1: Japanese Patent Application Publication 2002-90551;    Patent document 2: Japanese Patent Application Publication 1994-94925;    Patent document 3: Japanese Patent Application Publication 2005-235464;    Patent document 4: Japanese Patent Application Publication 2004-353066;    Patent document 5: Japanese Patent Application Publication 2005-129692;    Non Patent document 1: surface technology Vol. 55, No 12, 2004 P38 to P42